58 terms

Sky Science

Review Notes for Sky Science
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Altitude
the distance a heavenly body appears above the horizon
Annual Motion
the Earth's orbital motion around the Sun every year.
Asteroid Belt
the region of interplanetary space between Mars and Jupiter where most asteroids are found
Asteroid
a piece of rock or metal made up of material similar to that which formed the planets; mostly found in the asteroid belt between the inner and outer planets
Asterism
(astronomy) a cluster of stars (or a small constellation)
Astronomical units
The average distance between the earth and the sun; approximately 150 million kilometers.
Astronomy
the branch of physics that studies celestial bodies and the universe as a whole
Atmosphere
the mass of air surrounding the Earth
Axis
the center around which something rotates
Binary Stars
a group of two stars that circle around each other just as the moon circles around the earth; a double star
Black Hole
remnant of a star that is so dense that nothing, not even light, can escape its gravity field
Blue Moon
when there are two full moons in a month, the second one is this
Calibrate
make fine adjustments or divide into marked intervals for optimal measuring
Celestial Equator
an imaginary circle created by extending Earth's equator into space
Celestial Hemisphere
the heavens surrounding the earth that can be divided into two parts above the equator into northern and southern
Comet
(astronomy) a relatively small extraterrestrial body consisting of a frozen mass that travels around the sun in a highly elliptical orbit
Constellation
a configuration of stars as seen from the earth
Crater
a bowl-shaped depression formed by the impact of a meteorite
Crescent
any shape resembling the curved shape of the moon in its first or last quarters
Emit
give off, send forth, or discharge
Eclipse
one celestial body obscures another
Ecliptic
the great circle representing the apparent annual path of the sun
Equator
an imaginary line around the Earth forming the great circle that is equidistant from the north and south poles
Equinox
either of two times of the year when the sun crosses the plane of the earth's equator and day and night are of equal length
Galaxy
(astronomy) a collection of star systems
Gibbous
more than half, but less than fully illuminated moon
Gravity
(physics) the force of attraction between all masses in the universe
Hemisphere
one half of the sphere that makes up earth's surface
Inner Planets
The planets closest to the sun; Mercury, Venus, Earth, and Mars also known as the terrestrial planets
Latitude
an imaginary line around the Earth parallel to the equator
Light Year
the distance light travels in one year
Longitude
an imaginary great circle on the surface of the earth passing through the north and south poles at right angles to the equator
Lunar Eclipse
the blocking of sunlight to the moon that occurs when Earth is directly between the sun and the moon
Lunar Month
the period of time it takes the moon to revolve around the earth (approx. 29.5 days)
Magnitude
the brightness of a star
Meteor
(astronomy) any of the small solid extraterrestrial bodies that hits the earth's atmosphere
Meteorite
stony or metallic object that is the remains of a meteoroid that has reached the earth's surface
Midnight Sun
the sun visible at midnight (inside the arctic or antarctic circles)
Moon
any natural satellite of a planet
Moon Phases
new moon, (waxing or waning) crescent moon, quarter moon, (waxing or waning) gibbous moon, and full moon
Orbit
the path of an object as it revolves around another object in space
Outer Planets
Jupiter, Saturn, Uranus and Neptune. Much larger than the inner planets and have thick gaseous atmospheres. Called Gas Giants.
Planets
large, round bodies that revolve around a star
Pole Star
(A.K.A. - North Star) a visible star that is approximately aligned with the Earth's axis of rotation
Revolution
Earth's yearlong elliptical orbit around the sun
Rotation
spinning of Earth on its imaginary axis, which takes about 24 hours to complete and causes day and night to occur
Satellite
any natural or artificial object that revolves around another object
Solar Eclipse
occurs when the Moon passes directly between the Sun and Earth and casts a shadow over part of Earth
Solar Noon
time of day when the sun reaches its highest point in the sky for a given place on earth
Solar System
sun, planets, and all the other objects that revolve around the sun
Solstices
changes in season marked by summer & winter
Star
a huge ball of very hot gases in space
Sun
any star around which a planetary system evolves
Sundial
an instrument used to tell time using the shadow from the sun
Universe
everything that exists anywhere
Waning Moon
the phase in which the sunlight portion of the moon is beginning to shrink smaller and is now on the left side
Waxing Moon
the phase in which the sunlight portion of the moon is beginning to grow larger on the right side
Year
the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun